JPH06101815A - Premixing combustion burner and combustion device - Google Patents

Abstract

PURPOSE:To promote a mixing of fuel and air in a narrow space, improve a flame holding characteristics and prevent a back fire. CONSTITUTION:There are provided rotating vanes 3 for circulating air A flowed into a premixing chamber 9, a fuel injection nozzle 2 for injecting fuel Fp to the air A flowed into the premixing chamber 9, advancing vanes 4 having faces parallel to an axial direction of a burner, and a flame holder 6 for forming a circulating flow of combustion gas at a downstream side against the premixing gas Gm injected from a premixing gas injection port 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a premixed burner for premixing fuel and air and jetting the mixture, and a combustor equipped with the burner.

[0002]

2. Description of the Related Art As a low NOx combustion method for a gas turbine combustor, a lean premixed combustion method in which a fuel is premixed with an excess of air and then burned is the mainstream.
Like the combustor described in Japanese Patent No. 37117, 9
A combustor with 8% lean premixed combustion has already been proposed. The prerequisite for reducing NOx by this lean premixed combustion is that the fuel and air are thoroughly mixed before combustion. However, in a practical combustor, it is difficult to secure a sufficient space for mixing fuel and air, and it is necessary to develop a technique for mixing fuel and air well in a narrow space. Further, even if a part of the fuel and the air are mixed, there is a possibility of combustion, and therefore, it is necessary to develop a technique that does not form a flame in the mixing chamber for mixing the fuel and the air, that is, a flashback prevention technique.

By the way, as a technique for mixing fuel and air well in a narrow space, there is, for example, the one shown in JP-A-55-134221 and FIG. The former technique is
By swirling the air flowing into the premix chamber and injecting fuel into it, the flow of air is disturbed to increase the chances of contact with the fuel, and the residence time of air in the premix chamber is lengthened, It promotes mixing of fuel and air. Further, in this technique, since a swirl flow is formed even in the combustion chamber, high-temperature combustion gas circulates in the center of this swirl flow to serve as an ignition source, so that the flame holding effect is also improved. Also, the latter technology, like the former technology,
The swirl vanes 4 swirl the air flowing into the premix chamber 9,
While injecting fuel there to promote the mixing of fuel and air, a flame stabilizer 6 is provided slightly downstream of the premixed gas ejection port 5 to improve the flame retaining effect. Is.

[0004]

These conventional techniques are
In any case, although it is possible to promote the mixing of fuel and air and improve the flame holding property, a swirling flow is formed even in the vicinity of the premixed gas ejection port, and as a result, the pressure at the center of the swirling flow decreases, resulting in high temperature. There is a problem that backflow of combustion gas is likely to occur and a flashback is likely to occur. Therefore, the purpose of the present invention is to
Provided are a premix combustion burner capable of promoting mixing of fuel and air in a narrow space and improving flame holding property, and capable of preventing flashback, and a combustor including the burner. It is to be.

[0005]

A premixed combustion burner for achieving the above-mentioned object comprises a swirling means for swirling the air flowing into the premixing chamber and the air flowing into the premixing chamber. Fuel injection means for ejecting fuel by
A swirling strength changing means for weakening the swirling force of the premixed gas formed by mixing the swirling air and the fuel, and the swirling strength changing means on the downstream side of the premixed gas ejected from the premixed gas jet port. Flame holding means for holding a flame by forming a circulating flow of combustion gas formed by combustion of the premixed gas.

Here, the swirling means may be specifically constituted by swirl vanes provided so as to have a predetermined angle with respect to the burner axis direction. Further, it is preferable that the swirling strength changing means is configured by a rectilinear blade provided parallel to the burner axis direction, a honeycomb structure having a through hole parallel to the burner axis direction, or the like. Further, the flame holding means is provided on the burner central axis downstream of the premixed gas ejection port, and serves as a resistance for the premixed gas ejected from the premixed gas ejection port and the premixed gas ejection port. Can be formed of an expansion space forming member that forms a space that rapidly expands.

By the way, when a resistor is used as the flame holding means, it is preferable to connect it to the straight advancing blades constituting the turning strength changing means. Further, it is preferable that the straight-moving blade has a surface along the flow direction of the premixed gas that swirls in the downstream side portion.

[0008]

By mixing the fuel and air in the swirling flow, the mixing of the two is promoted. However, since the pressure drops at the center of the swirl flow, if this circulating flow is formed even at the premixed gas jet, the high temperature combustion gas will flow back to the part where the pressure is low, and flashback will occur. . Therefore, when the swirling flow is converted into a straight flow so that the swirling premixed gas becomes a substantially straight flow at least at the premixed gas jet, at least at the premixed gas jet, a portion with a low pressure is not formed. Flashback does not occur.

If a resistor (flame holder) with which the straight flow collides is provided downstream of the premixed gas jet after conversion into the straight flow.
A circulating flow is formed downstream of this resistor. This circulating flow is formed by high temperature combustion gas generated by combustion of the premixed gas. Therefore, the premixed gas burns using this high temperature combustion gas as an ignition source, and a stable premixed flame is formed around the circulating flow. Generally, in a combustor, it is difficult to mix fuel and air due to reasons such as difficulty in enlarging the premixing chamber due to dimensional constraints. It is possible to promote the mixing of the fuel and the air at the same time and prevent the flashback.

In the premixed combustion type gas turbine combustor,
Normally, two systems of burners are used: a pilot burner used when starting and having a low load, and a main burner used when the load is high. Of these, the pilot burner is used from the start, so the change range of the fuel flow rate and the air flow rate is large. Therefore, when the premixed combustion burner is used as the pilot burner, it is particularly difficult to mix the fuel and air, and flashback is likely to occur, but when the burner of the present invention is applied, the fuel and air are mixed well. Yes, and there is no flashback.

[0011]

EXAMPLES Various examples according to the present invention will be described below with reference to FIGS. In the description of various embodiments, the same parts are designated by the same reference numerals, and the duplicated description will be omitted. First, the first of the present invention
An example of the above will be described with reference to FIGS. 1 and 2. In the premixed combustion burner of the present embodiment, a swirl vane 3 for swirling the combustion air A flowing from an air inlet (not shown) into a cylindrical premix chamber 9 and a fuel. Fuel supply pipe 2 for supplying F and swirling premixed gas G
A straight advancing blade 4 for converting m into a straight advancing flow is provided.
A flame stabilizer 6 is provided on the downstream side of the premixed gas ejection port 5 to form a circulating flow of the combustion gas Ge formed by combustion of the premixed gas Gm on the downstream side of the premixed gas jet port 5 for flame holding. There is.

The fuel supply pipe 2 is arranged on the central axis of the burner, and the premixed fuel injection nozzle 2 is provided on the air inlet side thereof.
a is provided. The plurality of swirl vanes 3 are provided downstream of the premixed fuel injection nozzle 2a with the fuel supply pipe 2 as a central axis. The swirl vane 3 is provided so as to form an angle of several tens of degrees with respect to the central axis of the burner. Further, the plurality of rectilinear blades 4 are radially provided on the downstream side of the swirl blade 3 with the fuel supply pipe 2 as a central axis. The rectilinear blade 4 is provided in parallel with the central axis of the burner. The flame stabilizer 6 has a conical shape whose bottom surface faces the downstream side, and is provided at the downstream end of the fuel supply pipe 2. A diffusion fuel injection nozzle 7 is formed on the downstream end surface (bottom surface) of the flame stabilizer 6. The diffusion fuel injection nozzle 7 is connected to the flow path of the fuel supply pipe 2. Each straight blade 4 is connected to a flame stabilizer 6.

Next, the operation of this embodiment will be described with reference to FIG. Combustion air A flowing in from the air inlet
Is swirled by the swirl vane 3 to form a swirling flow. On the other hand, the premixed fuel Fp is ejected from the premixed fuel injection nozzle 2a and comes into contact with the combustion air A. The combustion air A and the premixed fuel Fp swirl together, and the turbulence of the flow of both becomes stronger, so that the mixing of both is promoted. Furthermore, since both are swirling, the substantial flow path length is longer and the contact time between both is longer than in the case of going straight, and mixing is further promoted.

The premixed gas Gm of the fuel Fp and the air A turns toward the premixed gas jet port 5 while swirling, and is converted into a straight flow by the straight advancing vanes 4. The premixed gas Gm converted into the straight flow collides with the flame stabilizer 6. Since a circulating flow of the high-temperature combustion gas Ge is formed on the downstream side of the flame stabilizer 6, the circulating combustion gas Ge serves as an ignition source and serves as a premixed gas Gm.
Burns stably. As described above, the flame stabilizer 6 has an extremely high temperature as an ignition source on the downstream side thereof, and is extremely high in temperature. However, since the flame stabilizer 6 is connected to the rectilinear blade 4, the heat of the flame stabilizer 6 can be diffused. That is, in the case of the present embodiment, the rectilinear blade 4 also has a function as a cooling means for the flame stabilizer 6.

As described above, in this embodiment, the swirl vane 3
By the action of, the mixing of the fuel Fp and the air A can be promoted. Further, at the premixed gas jet port 5, the premixed gas G
Since m is ejected as a straight flow, the pressure in the vicinity of the central axis of the burner does not decrease, and the high temperature combustion gas Ge does not flow back there, and it is also possible to prevent flashback.

Further, by the action of the flame stabilizer 6, the premixed gas Gm can be stably burned. Further, as in the conventional burner (shown in FIG. 12) described above, when there are a flame holding portion due to the swirling flow formed in the combustion chamber and a flame holding portion due to the flame stabilizer 6, as flame holding portions, Combustion oscillation tends to occur due to the flame holding action at these two places, whereas in the present embodiment, since the premixed gas Gm is ejected from the ejection port 5 as a straight flow, the flame holding location due to the swirling flow. Is not formed, and only the flame holding portion is formed by the flame stabilizer 6, so that combustion vibration does not occur and a very stable premixed flame can be obtained. The diffusion combustion fuel injection port 7 is used when the burner is ignited.

Next, a second embodiment according to the present invention will be described with reference to FIG. The premixed combustion burner of this embodiment is basically the same as that of the first embodiment except that the rectilinear vane 4a is not connected to the flame stabilizer 6. Therefore, this embodiment can also basically obtain the same effect as that of the first embodiment. However, in the straight-moving blade 4a,
Since the flame stabilizer 6 does not function as a cooling means, the flame stabilizer 6
In order to cool the flame stabilizer 6, it is preferable to provide a cooling water pipe along the fuel supply pipe 2 and the flame stabilizer 6 to cool the flame stabilizer 6.

Next, a third embodiment according to the present invention will be described with reference to FIG. The premixed combustion burner of the present embodiment uses the honeycomb structure 4b as a means for converting a swirling flow into a straight flow. The honeycomb structure 4b is formed with a plurality of through holes parallel to the central axis of the burner, and the wall surfaces of the through holes play the role of the straight advancing blades 4. As described above, when the honeycomb structure 4b is used, the rectifying action of the premixed gas can be enhanced more than the case where only a few straight blades 4 are used, and the position of the flame holding portion by the flame stabilizer 6 can be increased. It can be stabilized and more stable combustion can be achieved.

Next, a fourth embodiment according to the present invention will be described with reference to FIG. The premixed combustion burner of the present embodiment is the flame holder 6 and the straight advancing blades 4 in the first embodiment.
The shape of is changed. The flame stabilizer 6c of the present embodiment is
A space that abruptly expands from the premixed gas ejection port 5 is formed, and a circulating flow of combustion gas is formed on the outer peripheral side of the premixed gas ejection port 5. Further, in the rectilinear blade 4c of this embodiment, the upstream portion of the blade 4c is formed parallel to the direction along the direction of the swirl flow, and gradually becomes parallel to the burner central axis.
The downstream portion of the blade 4c is formed parallel to the burner central axis. Therefore, in the present embodiment, the swirling flow can be smoothly converted into a straight flow.

Next, a fifth embodiment according to the present invention will be described with reference to FIG. Flashback occurs because the pressure in the central portion of the swirling flow becomes low and hot combustion gas enters there. Therefore, even if the swirling flow is not completely converted into the straight flow, if the pressure drop in the central portion can be suppressed to some extent, the flashback can be prevented. The premixed combustion burner of the present embodiment is formed from such a point of view, and is provided with the straight advancing blades 4d for converting only the swirling flow in the vicinity of the central axis of the burner into the straight advancing flow. That is, in the present embodiment, unlike the other embodiments described above, the straight advancing blades 4, 4a, 4c having the same width as the inner diameter of the premixing chamber 9 are not provided, but the inner diameter of the premixing chamber 9 is larger than the inner diameter of the premixing chamber 9. Straight blade 4 with a small width
d is provided.

Further, in this embodiment, the swirl vane 4d is provided on the upstream side of the premixed fuel injection nozzle 2a. As described above, by providing the swirl vane 4d on the upstream side of the premixed fuel injection nozzle 2a, the fuel Fp is fed to the swirl vane 4d.
It is possible to prevent the gas from adhering to the burner and spurting out from the burner while growing and gathering. For this reason, the fuel Fp in the collected state is not burned, and NOx can be reduced. In addition,
It goes without saying that the swirl vanes may be provided upstream of the premixed fuel injection nozzle 2a in the previous embodiment as well.

Next, a sixth embodiment according to the present invention will be described with reference to FIGS. 7 and 8. The present embodiment is a gas turbine combustor including the premixed combustion burner described above.

The gas turbine combustor of the present embodiment has a casing 12 and a combustion inner cylinder 1 having a combustion chamber 19 formed therein.
3, a transition piece 14 for guiding the combustion gas Ge formed in the combustion chamber 19 to a gas turbine (not shown), a sub-premixed combustion burner 10 similar to that of the first embodiment, The main premixed combustion burner 20 is provided around it in an annular shape.

A sub-premix combustion burner 10 having a cylindrical premix chamber 9 is provided on the central axis of the casing 12. As shown in FIG. 8, the main premix combustion burner 20 has an annular premix chamber 29, and is provided around the sub premix combustion burner 10. In the vicinity of the air inlet 21 of the burner 20, swirl vanes 23 for swirling the inflowing combustion air A about the burner central axis of the sub-premixed combustion burner 10 are provided. Burner 20 spout 2
Downstream of 5, the cross-section is an isosceles triangle and the annular jet port 2
An annular flame stabilizer 26 corresponding to the shape of No. 5 is provided.
A slide ring 27 is provided at the air inlet 21 of the burner 20 to adjust the flow rate of inflowing combustion air. The premix chamber 29 is provided with a premix fuel injection nozzle 22 for ejecting the premix fuel therein.

By the way, since the premixing chamber 29 is formed in an annular shape, even if a swirling flow is formed therein, the pressure in the central portion is lowered so that the combustion gas Ge flows back into it. There is no such thing. However, when the flame stabilizer 26 is used, it is not preferable from the standpoint of combustion stability that the flame stabilizer 26 and the swirling flow flame stabilizer are formed as described above. Therefore, in this embodiment, the straight advance vane 24 is provided in the vicinity of the ejection port 25 in order to improve the combustion stability even in the annular main premixed combustion burner 20 which is basically free from the risk of flashback.

Next, the operation of the gas turbine combustor of this embodiment will be described. The combustion air A is pressurized by an air compressor (not shown) and then supplied to the combustor.
The combustion air A flows between the casing 12 and the combustion inner cylinder 13 and the transition piece 14, and each burner 1
It flows into the premixing chambers 9 and 29 of the burners 10 and 20 from the air inlets of 0 and 20.

At startup, the diffusion fuel injection nozzle 7
Diffuse fuel is injected into the combustion chamber 19 to form a diffusion flame. When the load on the gas turbine is low, the diffusion fuel injection nozzle 7 and the sub-premix combustion burner 10 are used.

When the load on the gas turbine increases, fuel is also supplied to the main premix combustion burner 20, and the burner 2
Combustion is also performed by 0. The flow rate of the combustion air A flowing into the burner 20 is adjusted by the slide ring 27. When the combustion air A flows into the premix chamber 29,
The swirl vane 23 creates a swirl flow, which mixes with the fuel Fp ejected from the premixed fuel injection nozzle 22. The swirling premixed gas Gm is converted into a straight flow by the straight blade 24, is jetted from the jet port 25, and is burned on the downstream side of the flame stabilizer 26. The combustion gas formed in the combustion chamber 19 is guided to the turbine blades 15 via the transition piece 14 and drives a gas turbine (not shown).

In this embodiment, since the combustion air and the premixed fuel are swirled, it is possible to promote the mixing of both without increasing the size of the premixing chamber or the combustor itself. Further, since the premixed gas is ejected from each of the burners 10 and 20 as a straight flow, it is possible to prevent flashback.

Next, a seventh embodiment according to the present invention will be described with reference to FIG. The gas turbine combustor of the present embodiment is provided with the annular main premixed combustion burner 20 of the sixth embodiment downstream of the sub premixed combustion burner 10. In other words, in the combustor, the main combustion chamber 19a in which the premixed gas from the main premixed combustion burner 20 burns, and the subcombustion chamber 19b in which the premixed gas from the sub premixed combustion burner 10 burns Is provided on the upstream side. The other configurations are basically the same as those of the gas turbine combustor of the sixth embodiment.

In this way, the main combustion chamber 19a and the auxiliary combustion chamber 19 are
b is provided, flames formed in the combustion chambers 19a and 19b are less likely to interfere with each other. For example, when the load is rapidly reduced during operation, the main premix combustion burner 2
It is necessary to stop the fuel supply to
If there is flame interference between the two, the main premix combustion burner 2
If 0 is extinguished, the flame of the sub-premixed combustion burner 10 may also be extinguished at the same time. However, in the combustor provided with the main combustion chamber 19a and the auxiliary combustion chamber 19b, the flames formed in the respective combustion chambers 19a and 19b are formed separately on the upstream side and the downstream side. Even if the flame is extinguished, the flame in the auxiliary combustion chamber 19b is not so affected. However, it goes without saying that such a combustor has a long overall length.

Next, an eighth embodiment according to the present invention will be described with reference to FIGS. The gas turbine combustor of this embodiment is provided with a plurality of premix combustion burners 10 of the first embodiment to cope with load fluctuations. At startup or when the load is low, the premix combustion burner 10 provided on the center axis of the combustor is used, and as the load increases, the surrounding premix combustion burners 10 are sequentially used.

In the present embodiment, all burners 1
Although the diffusion fuel injection nozzle 7 is provided at 0, this diffusion fuel injection nozzle 7 is basically used mainly at the time of start-up and low load, so it is not necessary to provide it to all the burners 10, and for example, the combustor central shaft is used. Burner 10 arranged above
You may make it provide only to. Further, in this embodiment,
The combustion inner cylinder 13 is provided with a slide ring 31 that allows air to flow into the combustion chamber 19 from the outer periphery thereof and adjusts the amount of inflow. Generally, when a large amount of air flows into the burner 10 when the load is low and the amount of injected fuel is small, stable combustion cannot be achieved. Therefore, in order to cope with such a case, when the load is low, a part of the air that has flowed into the combustor is directly introduced into the combustion chamber 19 from the slide ring 31 portion without passing through the burner 10. .

In the sixth, seventh, and eighth embodiments, the gas turbine combustor using the premixed combustion burner 10 described in the first embodiment has been described, but it will be described in other embodiments. The burner for premixed combustion described above may also be used in a gas turbine combustor. Also, in these examples,
Although only the gas turbine combustor is shown, it goes without saying that the burner for premixed combustion according to the present invention can be applied to other combustors.

[0035]

According to the present invention, since the fuel and the air are swirled, the mixing of the fuel and the air in a narrow space can be promoted. Further, the flame stabilizer can also improve the flame holding property. Further, since the premixed gas is ejected as a substantially straight flow at the burner ejection port, unlike the case where it is ejected as a swirl flow, the pressure at the center of the premixed gas does not drop and the high temperature combustion gas does not flow backward. Therefore, flashback can be prevented.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a burner for premixed combustion according to a first embodiment of the present invention.

FIG. 2 is an explanatory view for explaining the operation of the premixed combustion burner of the first embodiment according to the present invention.

FIG. 3 is an exploded perspective view of a burner for premixed combustion according to a second embodiment of the present invention.

FIG. 4 is an exploded perspective view of a premixed combustion burner according to a third embodiment of the present invention.

FIG. 5 is an exploded perspective view of a burner for premixed combustion according to a fourth embodiment of the present invention.

FIG. 6 is an exploded perspective view of a burner for premixed combustion according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a gas turbine combustor of a sixth embodiment according to the present invention.

FIG. 8 is a perspective view of a main part of a gas turbine combustor according to a sixth embodiment of the present invention.

FIG. 9 is a sectional view of a gas turbine combustor of a seventh embodiment according to the present invention.

FIG. 10 is a sectional view of a gas turbine combustor of an eighth embodiment according to the present invention.

FIG. 11 is a perspective view of an essential part of a gas turbine combustor according to an eighth embodiment of the present invention.

FIG. 12 is a sectional view of a conventional premixed combustion burner.

[Explanation of symbols]

2 ... Fuel supply pipe, 2a, 22 ... Premixed fuel injection nozzle, 3, 3d, 23 ... Swirl blade, 4, 4a, 4c, 4
d, 24 ... Straight blades, 4b ... Honeycomb structure, 5 ... Premixed gas jet port, 6, 6c, 26 ... Flame stabilizer, 7 ... Diffusion fuel jet nozzle, 9, 29 ... Premix chamber, 10 ... Premix Combustion burner, 12 ... Casing, 13 ... Combustion inner cylinder, 14 ...
Transition piece, 15 ... Turbine blade, 19 ... Combustion chamber, 19a ... Main combustion chamber, 19b ... Sub combustion chamber, 20 ... Main premix combustion burner, 21 ... Air inlet, 27, 31 ...
Slide ring.

Front Page Continuation (72) Inventor Tadataka Murakami 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Tomio Kuroda 3-1-1 1-1 Sachimachi, Hitachi City, Ibaraki Hitachi Hitachi Works, Ltd. (72) Inventor Shigeru Shodohata, 1-1, Sachimachi, Hitachi City, Ibaraki Hitachi Ltd., Hitachi Works

Claims (9)

[Claims] 1. A premix combustion burner comprising a premix chamber for premixing fuel and air, and a swirling means for swirling the air flowing into the premix chamber, and flowing into the premix chamber. Fuel injection means for ejecting the fuel to the discharged air, swirling strength changing means for weakening the swirling force of the premixed gas formed by mixing the swirling air and the fuel, and the premixed gas ejection port A flame holding means for forming a circulating flow of the combustion gas formed by combustion of the premixed gas on the downstream side of the premixed gas ejected from the flame holding means for flame holding. Characteristic burner for premixed combustion. 2. A premix combustion burner comprising a cylindrical premix chamber for premixing fuel and air, and a swirl vane for swirling the air flowing into the premix chamber, A fuel injection nozzle that injects the fuel into the air that has flowed into the chamber, a surface that is provided in the premix chamber and downstream of the swirl vanes and the fuel injection nozzle, and that is parallel to the burner axis direction. A straight advancing blade that has, and a pre-mixed gas ejected from the pre-mixed gas ejection port of the pre-mixing chamber, which forms a circulation flow of combustion gas formed by combustion of the pre-mixed gas on the downstream side of the pre-mixed gas. A burner for premixed combustion, comprising: a flamer. 3. The burner for premixed combustion according to claim 2, wherein the straight advancing vane has a surface along a flow direction of the premixed gas that swirls in a downstream side portion thereof. 4. A premix combustion burner comprising a cylindrical premix chamber for premixing fuel and air, and swirl vanes for swirling the air flowing into the premix chamber, A fuel injection nozzle that injects the fuel into the air that has flowed into the chamber, a premix chamber that is provided downstream of the swirl vanes and the fuel injection nozzle, and is arranged in a direction parallel to the burner axial direction. A honeycomb structure having a through hole, and a circulating flow of a combustion gas formed by combustion of the premixed gas on the downstream side of the premixed gas ejected from the premixed gas ejection port of the premixing chamber A premix combustion burner, comprising: 5. The flame stabilizer is a resistor provided downstream of the premixed gas ejection port and on the center axis of the burner, and serves as a resistance of the premixed gas ejected from the premixed gas ejection port. The burner for premixed combustion according to claim 2, 3 or 4, wherein 6. The flame stabilizer is a resistor provided downstream of the premixed gas ejection port and on the center axis of the burner, and serves as a resistance of the premixed gas ejected from the premixed gas ejection port. The burner for premixed combustion according to claim 2, 3 or 4, wherein the straight advancing blades and the flame stabilizer are connected to each other. 7. The burner for premixed combustion according to claim 2, 3 or 4, wherein the flame stabilizer is an expansion space forming member that forms a space that rapidly expands from the premixed gas ejection port. . 8. The premixed combustion burner according to claim 1, 2, 3, 4, 5, 6 or 7, and a combustion chamber in which the premixed gas ejected from the premixed combustion burner burns. A combustor characterized by being provided. 9. The premixed combustion burner according to claim 2, 3, 4, 5 or 6, and one or a plurality of main premixed combustion burners annularly arranged around the premixed combustion burner. A cylindrical combustion chamber in which the premixed gas ejected from the premixed combustion burner and the main premixed combustion burner burns, and a diffusion combustion nozzle that directly injects fuel into the combustion chamber, A gas turbine combustor characterized in that